Why losing sleep feels like a bang on the head

Ever feel like you've been hit on the head after a bad night's sleep? According to scientists, the thought isn't as far-fetched as it seems.

A study found going without sleep for just one night causes changes in the brain similar to those that occur after a blow to the head.

The researchers said the healthy young men examined in the study showed a spike in the same chemicals which indicate brain damage.

Professor Christian Benedict, of Uppsala University, Sweden, explained that the chemicals NSE and S-100B are biomarkers for brain damage, such as concussion.

He said: 'What we found was their levels in the blood rose in the group that went without sleep for a night.This was not to the extent that would happen after a head injury, for instance, but it was still significant.

"During sleep, the brain cleans itself of toxic substances and NSE and S-100B increase in response to these substances."

He said the findings back up previous research showing how the brain uses sleep to clean the brain of toxic substances.

Professor Benedict also said his study could support previous studies which linked a lack of sleep with increased risk of Alzheimer's, Parkinson's and multiple sclerosis.

The rise of the chemicals in the blood after sleep loss may suggest not getting enough sleep is conducive to a loss of brain tissue, he explained. Professor Benedict, whose study is published in journal Sleep, added: "In conclusion, the findings of our trial indicate a good night's sleep may be critical for maintaining brain health."

A third of the UK population suffer from sleep-related problems, while the average person now sleeps for only seven hours a night, compared with almost nine a few decades ago.

Many scientists believe irregular sleeping patterns lead to illnesses ranging from aches and pains to heart disease, while less than eight hours' sleep a night can lower the IQ the next day.